Mobile communication method, mobile communication system and access entity

ABSTRACT

An embodiment of the invention provides a communication system. The communication system includes a user equipment which is moving within a coverage of a first network and a second network and is configured to send a location update request to a third access entity of the second network; and the third access entity which is configured to receive the location update request from the user equipment, acquire information of a first access entity of the first network from the location update request and determine whether a predetermined condition is satisfied If the predetermined condition is not satisfied, the user equipment is paged through the first access entity, and if the predetermined condition is satisfied, the user equipment is not paged through the first access entity. As such, the situation that the UE is paged in an area where it is unlikely to appear can be avoided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of application Ser. No. 12/434,478filed on May 1, 2009, which is a continuation of International PatentApplication No. PCT/CN2007/070691, filed on Sep. 14, 2007. TheInternational Application claims the priority to Chinese PatentApplication No. 200610146106.8, filed on Nov. 3, 2006, Chinese PatentApplication No. 200610173372.X, filed on Dec. 30, 2006 and ChinesePatent application No. 200710138093.4, filed on Aug. 15, 2007. All ofthe aforementioned patent applications are hereby incorporated byreference in their entirety.

FIELD OF THE INVENTION

The present invention relates to communication field, and morespecifically, to mobile communication method, mobile communicationsystem and access entity.

BACKGROUND

Third Generation mobile communication technology (3G) generally refersto a new generation of a mobile communication system that integratesmultimedia communications, such as integrating wireless communicationand Internet-based communication. Such a mobile communication system isable to process various types of media data streams such as image,music, video streams and provide various information services such asweb page browsing, teleconference, and e-commerce. With the developmentof the communication technology, people are setting more and moredemanding requirements for the mobile communication. The networkarchitecture and protocols of the existing 3rd Generation PartnershipProject (3GPP) no longer satisfy users' high demand for mobilecommunication. Accordingly, 3GPP proposed a concept of an evolvednetwork for fulfilling future communication requirements.

In particular, to ensure the competitive edge of the 3GPP in the furtherdevelopment, especially the capability of the 3GPP system for processingrapidly increasing IP (Internet protocol) data services, the 3GPP haslaunched a Long Term Evolution (LTE) program and a System ArchitectureEvolution (SAE) program. The purpose of the LTE is to provide an evolvedcommunication network (such as SAE network or LTE network, by way ofexample) which can reduce time delay, increase user data rate, enhancesystem capability and coverage, and save overall cost of operators ofthe network. Meanwhile, the backward compatibility of the evolvednetwork structure toward the existing network is also an importantfactor to consider.

The evolved network structure needs to meet the following requirements:

(1) a basic IP connection needs to be set up in the evolved networkduring an initial stage when a user equipment accesses the network.

(2) the evolved network structure must minimize the delay of the userdata.

(3) each function module in the evolved network architecture should bedefined in such a way to avoid functional overlapping or repetition soas to avoid unnecessary signaling and time delay.

FIG. 1 illustrates a general network architecture derived from the aboverequirements. The network architecture mainly includes four logicfunction modules: a Mobility Management Entity (MME), a user planeentity (UPE) gateway (which is a Serving Gateways (S-GW) or anintegrated gateway including a Serving GW and a PDN Gateway (P-GW)), anLTE Radio Access Network (LTE RAN), and a Home Subscriber Server (HSS).The MME is a mobility management module responsible for mobilitymanagement for a control plane. The mobility management includesmanagement for user context and mobility state, assignment ofinformation such as user temporary identity, mobility state, trackingarea (TA), and verification of user identity. The MME corresponds to acontrol plane of a Serving GPRS Support Node (SGSN) in the UniversalMobile Telecommunications System (UMTS). The S-GW is responsible forinitiating paging downstream data of a user equipment (UE) in an idlemode, managing and storing UE context, IP bearer parameters and routinginformation in the network, and managing UE' s mobility control planeanchor and user plane anchor functions between the 3G and the SAEnetwork. The S-GW corresponds to a data plane of SGSN in the currentUMTS. The P-GW is responsible for a user anchor function that UEaccesses the packet data network. The P-GW has packet routing andforwarding functions and is responsible for policy charging enhancement,packet filtering function based on each user, and is coupled to the S-GWto carry and deliver control information such as create/modify/delete.The LTE RAN is a radio access network for the evolved network. The nodestherein are not defined specifically. Generally, the LTE RAN includes anevolved base station (eNodeB), and may also include a control planeserver (CPS) logic entity. In a logic sense, the LTE RAN can be treatedas a Long Term Evolution Radio Access Network (LTE-RAN) entity.

Since network structures adopting different radio access technologies(RATs) may exist simultaneously in a real application, networkregistration procedures may be aroused in a “ping-pang” manner due tothe change between different networks when UE is moving betweendifferent RATs (e.g., between a conventional network (i.e. a 2G/3Gnetwork) and an evolution network such as an SAE network). Asillustrated in FIG. 2, a Routing Area 1 (RA1) and a Routing Area 2 (RA2)are routing areas for an existing 2G/3G network. The UE of the existing2G/3G network always initiates a Routing Area Update (RAU) procedurewhen switching a routing area (RA). Of course, even if UE does notswitch RA, there is also a periodic location update procedure, thefunction of which is to inform the network that the UE is still in thenetwork currently so as to prevent the network from keeping paging UEwithout knowing that the UE leaves the network. A network registrationprocedure due to the movement of the UE is now illustrated below.

In FIG. 2, TA1, TA2, TA3, TA4 are tracking areas in the evolved network.TA is similar to RA in the 2G/3G network. When a multi-mode UE is movingbetween different RA and TA, to ensure that the UE can be paged innetworks adopting different RATs, the UE needs to register with RA andTA it enters. If the UE enters RA1, the UE needs to register with theSGSN of the 2G/3G network. When the UE enters TA1, the UE further needsto register with the MME of the evolved network. When the UE exits TA1and re-enters RA1, the UE needs to register with the SGSN of the 2G/3Gnetwork again. However, the method results in frequent networkregistration procedures for ensuring paging, causing therebyconsiderable consumption of the registration signaling.

To solve this problem, various methods in conventional arts have beenproposed to avoid frequent network registrations and a severe waste inthe air-interfaces.

Currently, a schema for lessening the registration/update influence onair-interfaces is imposed by UE in the idle mode when entering networkswith different RATs. The idea of the schema is that the UE registerswith an access network (a 2G/3G network or an evolved network) after theUE attaches to the network. Then, the UE registers with another accessnetwork when the UE moves to the other access network. As such, the

UE may register with both access networks. After that, when the UE movesbetween corresponding RAs or TAs of these two networks, the UE may notinitiate any registration procedure. Both the access entities in thesetwo access networks with which the UE registers contain corresponding UEcontext.

Now, the procedure of the UE first attaching to the SAE and then movingto the 2G/3G network is illustrated below.

As illustrated in FIG. 3, at step 301, the UE attaches to the SAE,sending an “attach request” message to the MME.

At step 302, the MME may acquire context from the HSS and initiate anauthentication procedure with the UE.

At step 303, the UE returns an authentication response to the MME. Ifthe authentication passes, it indicates that the UE has registered withthe MME successfully. The MME assigns an SAE temporary mobile subscriberidentity (S-TMSI)/SAE routing area (S-RA, i.e., TA) and a default IPaddress to the UE. The S-TMSI denotes a temporary mobile subscriberidentity of the SAE network. The S-RA demotes the RA of the SAE, i.e.,TA.

At steps 304 and 304′, the MME may register with the HSS (if the MMEalready contains the UE context, there is no need for the MME to acquirethe context from the HSS).

At step 305, the MME confirms that the UE has attached to the networksuccessfully and allows the UE to enter. The MME assigns a S-TMSI/S-RAto the UE and sends information of the default IP address to the UE.

At step 306, after the UE switches from a different RAT to the 2G/3Gnetwork, the UE initiates an RAU procedure and carries a S-TMSI/S-RAassigned by the MME to the SGSN (and may also carry parameters such asTMSI/RA assigned by the SGSN).

At steps 307 and 307′, the SGSN may send an SGSN Context Request messageto an associated MME to request the UE context. After the MME receivesthe request message, the MME sends the associated context to the SGSN.Such procedure is referred to as a Context Retrieval procedure.

At step 308, authentication procedure may be performed. The SGSN mayregister with the HSS, as illustrated in steps 309 and 309′ (the SGSNmay not register with HSS, but may treat the MME as the HSS).

At step 310, the SGSN confirms the receipt of the context and maytrigger the MME to transfer data.

At step 311 and 311′, the SGSN may update Packet Data Protocol (PDP)context with the MME because the MME, at the user plane, is similar toan original GPRS Gateway Support Node (GGSN).

At step 312, the SGSN assigns U-TMSI (UMTS TMSI, Temporary MobileSubscriber Identity of UMTS)/U-RA (Routing Area of UMTS) and S-TMSI/S-RAto the UE. After that, no update registration message needs to be sentwhen the UE moves between U-RA and S-RA. The U-TMSI denotes a temporarymobile subscriber identity of the 2G/3G network. U-RA demotes the RA ofthe 2G/3G network.

At step 313, the UE returns an RAU completion message.

The procedure that the UE first attaches to the 2G/3G network and thenmoves to the SAE network is similar to the procedure that the UE firstattaches to the SAE network and then moves to the 2G/3G network asillustrated in FIG. 4, which will not be detailed herein.

Briefly, the UE first attaches to the SGSN. The SGSN registers with theHSS. Then, the UE enters the SAE network and initiates a RAU andretrieves context from the SGSN. The MME registers with the HSS andassigns a S-RA/S-TMSI to the UE. The UE does not need to initiate alocation update/registration message when moving between the registeredRA and S-RA (in terms of TA, RA, the UE may be assigned with a pluralityof areas of the SAE network or the 2G/3G network, such as several S-RAs.Then, the UE does not need to initiate the update message when movingbetween the registered areas assigned by the networks). When the UEmoves to areas beyond registered S-RA/RA, the UE needs to initiate anupdate message. It should be noted that if the SGSN is not replaced, theSGSN registration procedure may be unnecessary.

It is discovered that the above schema encounters at least the followingissues in practical application. The network side may page the UE in anunnecessary paging area, reducing efficiency for paging the UE.

The root cause behind such problem is that in the current registrationprocedure, after the UE enters an RAT network, the UE performsregistration and is assigned with TA/RA of the RAT network. After the UEenters another RAT network, the UE initiates an update procedure and isassigned with RA/TA of another RAT network. Then, the UE does not needto initiate the update procedure when moving between the registered RAand TA. When the UE enters a new RA or TA, the UE needs to initiate anupdate message. The SGSN/MME of the new RA/TA establishes an associationwith an access entity (MME/SGSN) of another RAT network. Accordingly,the UE does not need to initiate an update message when moving betweenthe new RA/TA and the TA/RA assigned by the access entity of another RATnetwork.

As illustrated in FIG. 5, the TA is a registered area of the SAE networkwhile RA is a registered area of the UMTS. According to the currentschema, the UE registers with the MME when entering TA1 and initiates anUMTS location update after entering the RA1 and registers with the SGSN.Then, the UE does not need to initiate a location update procedure whenmoving between TA1 and RA1. As such, location update procedures due toping-pang movement between two RAT networks can be saved. That is, thenotion of the TA may help to avoid ping-pang update due to different TAsin one RAT.

After UE moves to RA2, the UE initiates a location update. Then, the UEdoes not need to initiate a location update procedure between TA1 andRA2 (when UE moves back to RA1, the UE still needs to initiate alocation update. After that, the UE does not need to initiate a locationupdate when moving between TA1 and RA1).

If the UE does not need to initiate a location update procedure whenmoving between TA1 and RA2, and the UE will initiate a location updateprocedure again when moving back from TA1 to TA2. After that, the UEdoes not need to initiate a location update procedure when movingbetween TA2 and RA2.

Likewise, when the UE moves to TA3, TA4 till TA5 again, the UE does notneed to initiate a location update procedure when finally moving betweenTA5 and RA2.

However, it can be seen from the FIG. 5 that it is impossible for the UEto move directly between the TA5 and the RA2. In addition, the MMEmanaging the TA5 may not be associated with the SGSN managing the RA2(e.g., the MME and the SGSN belong to different Public Land MobileNetworks, and have no roaming interface, or due to distance reason, the“associable SGSN list” configured on the MME does not include SGSN whichthe RA2 belongs to). Therefore, a signaling procedure between the TA5and the RA2 is not necessary. Since the UE can only enter an area aroundthe TA5 in a next step and the UE is unlikely to enter the RA2, it ismeaningless to associate the SGSN of the RA2 with the MME of the TA5.However, the RA2 still needs to be paged during a paging period, whichmay cause a mass of paging and reduce efficiency for paging the UE.

Alternatively, in practice, the UMTS is an all-covered network. The SAEis a network covering hot spots, as illustrated in FIG. 6. After UEregisters with TA1 and RA1, the UE moves from RA1 to RA2 and to RA3. TheUE does not need to initiate an update procedure when moving between TA1and RA3. Alternatively, after UE registers with TA1 and RA1, the UEmoves from TA1 to TA2 and to TA3 and to TA4. Then, the UE does not needto initiate an update procedure when moving between RA1 and TA4.

Usually, the area with which the UE registers (after registering withtwo different RAT networks) is referred to as UE registered area ornon-update area. With no optimization such as priority residence, thepaging area of the UE is the UE registered area (non-update area).However, actually, since the UE may not move directly between these twoRA/TA (location update procedure is bound to be incurred during moving),the necessary paging area of UE is just the registered area of the RATnetwork where the UE currently locates. Therefore, the network side maypage UE in an unnecessary paging area, reducing efficiency for pagingUE.

After ISR (Idle mode Signaling Reduction) is activated, the HSS mayrecord entity information of two systems. That is, the HSS may recordinformation of SGSN and MME with which the UE registers, i.e., dualregistration. However, single registration refers to that the HSS mayonly record information of the entity in one system after ISR isactivated (i.e., record the information of the entity with which UEinitiates the update most recently). However, information of entities inother system with which the UE registers is stored in another systementity. If the UE first registers with the 2G/3G network first, then theHSS records information of SGSN with which the UE registers (a locationupdate message is sent to HSS via SGSN). When UE moves to another RATi.e. the SAE system and initiates a location update, the UE againregisters with MME in the SAE system. The ISR is then activated. Also,the MME sends a location update to HSS. The HSS records the informationof MME and deletes the information of SGSN. However, the information ofSGSN is stored in the MME. The SGSN and the MME all record UEinformation. However, the HSS only saves entity information of onesystem.

SUMMARY OF THE INVENTION

In view of this, the present invention provides a mobile communicationmethod, a mobile communication system and an access entity so as toimprove the efficiency for paging UE.

In a first aspect of the invention, a system is provided according toone embodiment of the present invention.

The system is implemented in a scenario where a user equipment is movingwithin a coverage of a first network and a second network, wherein theuser equipment is registered with both a first access entity of thefirst network and a second access entity of the second network, and afirst association is established between the first access entity and thesecond access entity so that when the user equipment needs to be paged,the user equipment is paged in a paging area administered by the firstaccess entity and a paging area administered by the second access entityaccording to the first association.

The system includes:

the user equipment, configured to send a location update request to athird access entity of the second network; and

the third access entity, configured to receive the location updaterequest from the user equipment, acquire information of the first accessentity from the location update request and determine whether apredetermined condition is satisfied.

The predetermined condition includes one or more of the following:

a distance between an area where the user equipment is currently locatedand the paging area administered by the first access entity exceeds apredetermined threshold;

the third access entity cannot be associated with the first accessentity; and

the speed of the user equipment in a current access entity system islower than a threshold.

If the predetermined condition is not satisfied the user equipment ispaged through the first access entity, and if the predeterminedcondition is satisfied, the user equipment is not paged through thefirst access entity.

In a second aspect of the invention, a method is provided. The method isfor use in a scenario where a user equipment is moving within a coverageof a first network and a second network is provided according to oneembodiment of the present invention, wherein the user equipment isregistered with both a first access entity of the first network and asecond access entity of the second network, and a first association isestablished between the first access entity and the second access entityso that when the user equipment needs to be paged, the user equipment ispaged in a paging area administered by the first access entity and apaging area administered by the second access entity according to thefirst association.

The method includes:

sending, by the user equipment, a location update request to a thirdaccess entity of the second network.

The location update request triggers the third access entity to acquireinformation of the first access entity from the location update requestand determine whether a predetermined condition is satisfied.

The predetermined condition comprises one or more of the following:

a distance between an area where the user equipment currently locatesand the paging area administered by the first access entity exceeds apredetermined threshold;

the third access entity cannot be associated with the first accessentity; and

the speed of the user equipment in a current access entity system islower than a threshold.

If the predetermined condition is not satisfied, the user equipment ispaged through the first access entity; and if the predeterminedcondition is satisfied, the user equipment is not paged through thefirst access entity.

In the third aspect of the invention, a user equipment is providedaccording to one embodiment of the present invention. The user equipmentis moving within a coverage of a first network and a second network, andis registered with both a first access entity of the first network and asecond access entity of the second network; wherein a first associationis established between the first access entity and the second accessentity so that when the user equipment needs to be paged, the userequipment is paged in a paging area administered by the first accessentity and a paging area administered by the second access entityaccording to the first association.

The user equipment includes:

a transmitter, configured to send a location update request to a thirdaccess entity of the second network.

The location update request triggers the third access entity to acquireinformation of the first access entity from the location update requestand determine whether a predetermined condition is satisfied.

The predetermined condition comprises one or more of the following:

a distance between an area where the user equipment currently locatesand the paging area administered by the first access entity exceeds apredetermined threshold;

the third access entity cannot be associated with the first accessentity; and

the speed of the user equipment in a current access entity system islower than a threshold.

If the predetermined condition is not satisfied, the user equipment ispaged through the first access entity; and if the predeterminedcondition is satisfied, the user equipment is not paged through thefirst access entity.

By comparison, the difference between the technical solutions of thepresent invention and the prior art lies in that, in the process of theaccess entity performing a location update for the UE or performing a UEaccess procedure, the present invention may include determining whetheror not the area which the UE currently locates satisfies a predeterminedcondition. If the predetermined condition is met, the UE is paged in apaging area administered by the access entity and it is prohibited topage the UE in the paging area administered by the originally associatedaccess entity in the other network when the UE needs to be paged. Assuch, the situation that the UE is paged in an area where it is unlikelyto appear can be avoided, so that the efficiency for paging the UE isimproved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a conventional architecture of an evolved network;

FIG. 2 is a conventional network structure adopting different RATs atthe same time;

FIG. 3 is a conventional registration procedure of a UE first attachingto a SAE network and then moving to a 2G/3G network;

FIG. 4 is a conventional registration procedure of a UE first attachingto a 2G/3G network and then moving to a SAE network;

FIG. 5 is a conventional location schematic of TAs and RAs;

FIG. 6 is another conventional location schematic of TAs and RAs;

FIG. 7 is a flowchart of a mobile communication method according to afirst embodiment of the present invention;

FIG. 8 is a flowchart of a mobile communication method according to asecond embodiment of the present invention;

FIG. 9 is a flowchart of a mobile communication method according to athird embodiment of the present invention;

FIG. 10 is a flowchart of a mobile communication method according to afourth embodiment of the present invention;

FIG. 11 is a flowchart of a mobile communication method according to afifth embodiment of the present invention;

FIG. 12 is a flowchart of a mobile communication method according to asixth embodiment of the present invention;

FIG. 13 is a flowchart of a mobile communication method according to aseventh embodiment of the present invention;

FIG. 14 is a flowchart of a mobile communication method according to aneighth embodiment of the present invention;

FIG. 15 is a block diagram of an access entity according to oneembodiment of the present invention; and

FIG. 16 is a block diagram of a bearer transfer system according to oneembodiment of the present invention.

DETAILED DESCRIPTION

Illustrations are made to embodiments of the present invention inconnection with the accompanying drawings.

In one embodiment of the present invention, when UE is moving in twonetworks with different RATs, the UE may register respectively withaccess entities in the two networks. These two access entities areassociated with each other. When the UE moves to a new TA or RA andinitiates a TAU (tracking area update) or RAU (routing area update)procedure or other access procedures (e.g., service request, pagingresponse, periodic location update, PDP context activation), the accessentity in the area where the UE currently locates determines based onthe area where the UE currently locates whether a predeterminedcondition is met. If the predetermined condition is met and when the UEneeds to be paged, the UE is paged in the paging area administered bythe access entity and it is prohibited to page the UE in the paging areaadministered by the originally associated another access entity in theother network. Such a predetermined condition may be that a distancebetween the area where the UE currently locates and a paging areaadministered by another access entity originally associated with thearea where the UE currently locates is above a predetermined threshold;or these two areas are not adjacent to each other; or the access entityin the area where the UE currently locates cannot to be associated withthe another access entity; or the time that UE stays in the current areareaches a time threshold. The predetermined condition is triggered bytime or events (e.g., location update, terminal initiating a MobileOriginated Call (MOC), mobile station termination initiating a MobileTerminating Call, etc.). If the access entity in the area where the UEcurrently locates determines, based on the area where the UE currentlylocates, that the predetermined condition is not met, then, when the UEneeds to be paged, the UE is paged in a paging area administered by theaccess entity in the area where the UE currently locates and a pagingarea administered by the originally associated access entity in anothernetwork.

With the TA, RA concept, the UE may be assigned with a plurality ofareas in the SAE network or the 2G/3G network. If a plurality of S-RAsare assigned, the UE does not need to initiate an update message whenmoving among registered area assigned by the same network. Embodimentsof the present invention are illustrated by way of an example where eachRAT network assigns an RA or TA to the UE. However, the embodiments ofthe present invention should not be so limiting.

A first embodiment of the present invention is detailed below. Theembodiment relates to a mobile communication method. In the embodiment,the access entity in the area where the UE currently locates deletes theassociation with an originally associated another access entity orinforms the another access entity to set the UE to a detached state soas to prohibit paging the UE in the paging area administered by theother access entity which was originally associated with the accessentity in the area where the UE currently locates.

The embodiment is illustrated by way of an example where the UEregisters with RA2 (as illustrated in FIG. 5) and moves to TA5 andinitiates a TAU procedure after the UE moves from TA4 to TA5. Aprocessing procedure of the access entity MME in the area where the UEcurrently locates is illustrated below.

As shown in FIG. 7, in step 701, since the UE enters a new TA, a TAUprocedure is initiated. A TAU update message may carry S-RA, S-TMSI, RA,TMSI or parts of these parameters. The parameters described in variousembodiments of the present invention are not limited in this respect.The S-TMSI refers to a temporary mobile subscriber identity of the SAEnetwork. The S-RA refers to RA of the SAE, i.e., TA. The TMSI refers toa temporary mobile subscriber identity of the UMTS network. The RArefers to RA of the UMTS.

At step 702, if the access entity of the new TA is an access entity thatthe UE has not registered with, the new access entity may go through acontext retrieval procedure. That is, if the MME of the new TA where theUE moves to is not the same MME with which the UE registered, i.e., theold MME, the new MME needs to retrieve necessary context from the oldMME or/and SGSN or/and HSS.

Step 703 is an optional procedure such as a safety authentication.

At step 704, if the MME of the new TA where the UE moves to is not thesame MME which the UE registered with, the new MME may initiate aregistration procedure with the HSS.

At step 705, the new MME determines if the area where the UE currentlylocates satisfies a predetermined condition. For instance, the new MMEdetermines if the distance between the area where the UE currentlylocates and the paging area administered by another access entityoriginally associated with the area where the UE currently locates isabove a predetermined threshold; or if these two areas are not adjacentto each other; or if the access entity in the area where the UEcurrently locates cannot be associated with another access entity whichwas originally associated with the area where the UE currently locates;or the time that UE stays in the current area reaches a time threshold;or the speed of the UE in the current area is lower than a threshold.That is, the new MME determines if the distance between TA5 and RA2 (RA2is retrieved from messages sent by UE or from the context retrievalprocedure) exceeds a threshold or TA5 and RA2 are not adjacent to eachother or the association between MME and SGSN is limited (e.g., SGSN isnot in the “associable SGSN list” of the new MME) or the time that theUE resides in the RAT exceeds a threshold (if the UE stays most of thetime in one area, the possibility that the UE is still within the areais high, for instance, the user works at an office or go home and sleep,etc.) With several times of location updates, or being triggered byother access procedures, or being triggered by a time event, embodimentsof the present invention can be applied. For instance, paging resourcecan be saved by de-associating/de-registering the UE from another RATarea and preventing the network from paging in other areas. When the UEfurther moves to another RAT area, the UE initiates a registration andre-establish the association). The RA2 may be acquired from the messagesent from UE or acquired from the context retrieval procedure.

If the distance between TA5 and RA2 exceeds a certain threshold, or theyare not adjacent to each other, or the association between a new MME andthe SGSN is limited, or the time that the UE resides in an RAT exceeds athreshold, the new MME may initiate a message such as a detach requestor association cancellation request and inform the SGSN to set the UE toa detach state or de-register the UE, or mark the UE so as to indicatethat the SGSN does not need to page this UE.

At step 706, after SGSN receives the message, the SGSN sets the UE tothe detached state or de-registers the UE, or marks the UE to indicatethat the SGSN does not need to page this UE.

At step 707, the SGSN returns a response to the new MME.

At step 708, the new MME cancels association with the originallyassociated SGSN, i.e., deletes the address information of the SGSN.

Then, the procedure might proceed to step 709. The UE's current accessentity sends a notification of a change of a user plane to S-GW (IASA).The S-GW prohibits sending data or a paging request to access entitiesin another network. Step 709 and step 710 are not limited in sequence.

At step 710, the new MME sends a TAU Accept (TAU completion) message.The message only contains a SAE ID or corresponding instructions for theUE. When the UE enters a new RA again, the UE initiates an accessprocedure using the SAE ID. The reason for doing this is that the newaccessed SGSN is not able to retrieve related context from the old SGSN.

It is appreciated that, in this embodiment, when the new access entityMME determines that it is impossible that the MME is associated with itsoriginally associated access entity SGSN in another RAT network, or TA5where the UE currently locates is not adjacent to paging area RA2administered by another access entity SGSN or the distance between TA5and RA2 exceeds a certain threshold, the MME may send a detach requestor an association cancellation request, informing another access entitySGSN to set the UE state recorded thereon to a detach state or tode-register the UE, or cancel association between the two access entity.As a result, the paging won't be performed in the paging areaadministered by the SGSN and the situation that the UE is paged in anarea where it is unlikely to appear can be avoided, so that theefficiency for paging the UE is improved.

It should be noted that the case where the access entity in the areawhere the UE currently locates is SGSN and another RAT entity is MME issimilar to the present embodiment, which is omitted herein for brevity.

A second embodiment of the present invention relates to a mobilecommunication method. The embodiment is likewise illustrated by way ofan example where a UE registers with RA2 (as illustrated in FIG. 5) andmoves to TA5 and initiates a TAU procedure after the UE moves from TA4to TA5. A processing procedure of the access entity MME in the areawhere the UE currently locates is illustrated below. The differencebetween the present embodiment and the first embodiment is that, in thefirst embodiment, the access entity in the area where the UE currentlylocates deletes the association with the originally associated anotheraccess entity or informs the another access entity to set the UE to adetached state so as to prohibit paging the UE in the paging areaadministered by the other access entity which was originally associatedwith the access entity in the area where the UE currently locates.However, in the present embodiment, the access entity in the area wherethe UE currently locates modifies association in order to prohibitpaging the UE in the paging area administered by the other access entitywhich was originally associated with the access entity in the area wherethe UE currently locates.

Specifically, as shown in FIG. 8, step 801 to step 804 are identical tostep 701 to step 704, the description of which is omitted herein forbrevity.

At step 805, the new MME determines if the area where the UE currentlylocates satisfies a predetermined condition. For instance, the new MMEdetermines if the distance between the area where the UE currentlylocates and the paging area administered by another access entityoriginally associated with the area where the UE currently locates isabove a predetermined threshold; or if these two areas are not adjacentto each other; or the time that UE stays in the current area reaches atime threshold or the speed of the UE in the current area is lower thana threshold; or if the access entity in the area where the UE currentlylocates is not able to be associated with another access entity whichwas originally associated with the area where the UE currently locates.That is, the new MME determines if the distance between TA5 and RA2 (theRA2 is acquired from the messages sent by the UE or from the contextretrieval procedure) exceeds a certain threshold or if TA5 and RA2 arenot adjacent to each other or the association between MME and SGSN islimited (e.g., the SGSN is not in the “associable SGSN list” of the newMME). The RA2 may be acquired from the message sent from the UE oracquired from the context retrieval procedure.

If the distance between TA5 and RA2 exceeds a certain threshold or TA5is not adjacent to RA2 or the association between the new MME and SGSNis limited or the time that the UE stays at an RAT exceeds a certainthreshold, the new MME may select an access entity administered by an RAwhich is adjacent to TA5 as another new access entity associated withthe current access entity MME. Since there is a plurality of RAs whichare adjacent to TA5, the new MME may select, according to a selectionalgorithm, an adjacent area where UE has a high probability to moveinto, i.e., the RA where the UE has a high probability to move into, ormay select an RA adjacent to TA5 randomly. Alternatively, the newlyassociated access entity SGSN may select, according to a selectionalgorithm, an RA where the UE has a high probability to move into or mayselect an RA adjacent to TA5 randomly as a paging area administered bythe newly associated SGSN for the UE.

At step 806, the new MME sends a location update request (or UpdateLocation request) to the SGSN, carries the RA adjacent to TA5 selectedby the MME, e.g., RA3. Alternatively, the new MME may send TA5information and have the SGSN select an appropriate RA.

If the newly associated SGSN selected by the new MME is not the originalSGSN with which the UE registered, a context retrieval procedure may beperformed such that the new SGSN may obtain necessary context of the UE,as illustrated in step 807.

If the newly associated SGSN selected by the new MME is not the originalSGSN with which the UE registered, the newly associated SGSN may alsoneed to initiate a registration with a Home Subscriber Server (HSS), asillustrated in step 808.

At step 809, if the newly associated SGSN accepts the location update,the newly associated SGSN returns a response to the new MME. Theassociation between the MME and SGSN is established (i.e., the new MMEacquires address information of the newly associated SGSN, the newlyassociated SGSN acquires address information of the new MME) asillustrated in step 809′.

At step 810, the MME sends a TAU Accept message. The message containsRA/TMSI ID of the new UMTS (i.e., RA3). Then, the UE does not need toinitiate an update message when moving between TA5 and RA3. When UEneeds to be paged, paging will be initiated in TA5 and RA3.

It is appreciated that, in the present embodiment, when the new accessentity MME determines that the current MME is unlikely to be associatedwith the originally associated access entity SGSN in another RATnetwork, or the TA5 where the UE currently locates is not adjacent tothe paging area RA2 administered by another access entity SGSN or thedistance in-between exceeds a certain threshold, the MME may activelylet the UE register with the access entity SGSN in another RAT networkadjacent to the new access entity and the SGSN is treated as the newlyassociated access entity. The newly associated SGSN assigns new TMSI forUE such that the UE does not need to initiate an update message whenmoving within TA5 and RA3. When the UE needs to be paged, the UE ispaged in the paging area (i.e., TA5 and RA3) administered by the newlyassociated SGSN. Consequently, the network side may conduct pagingwithin the area where the UE is likely to be within. As such, theefficiency for paging UE is further improved.

A third embodiment of the present invention relates to a mobilecommunication method. The embodiment is likewise illustrated by way ofan example where UE registers with RA2 (as illustrated in FIG. 5) andmoves to till TA5 and initiates a TAU procedure after UE moves from TA4to TA5. A processing procedure of the access entity MME in the areawhere the UE currently locates is illustrated below. The differencebetween the present embodiment and the first embodiment is that, in thefirst embodiment, the access entity in the area where the UE currentlylocates deletes the association with another access entity or informsthe another access entity to set UE to an detach state so as to prohibitpaging the UE in the paging area administered by another access entitywhich was originally associated with the access entity in the area wherethe UE currently locates. However, in the present embodiment, the UE isprohibited to be paged in the paging area administered by the originallyassociated another access entity by setting the association between theaccess entity in the area where the UE currently locates and theoriginally associated another access entity as invalid. When the UEneeds to be paged, the UE is paged only in the paging area administeredby the access entity in the area where the UE currently locates. Thedifference between setting the association as invalid and cancelling theassociation is that, in the case of setting the association as invalid,the access entity in the area where the UE currently locates stillrecords address information of the associated another access entity.Thus, the paging won't be occurred in the network of another accessentity while the UE may still in an attach state in another accessentity. Of course, MME may also inform the S-GW to stop transmittingdata to another access entity.

Specifically, as shown in FIG. 9, step 901 to step 904 are identical tostep 701 to step 704, the description of which is omitted herein forbrevity.

At step 905, the new MME determines if the area where the UE currentlylocates satisfies a predetermined condition. For instance, the new MMEdetermines if the distance between the area where the UE currentlylocates and the paging area administered by another access entityoriginally associated with the area where the UE currently locatesexceeds a predetermined threshold; or if these two areas are notadjacent to each other; or the time that UE stays in the current areareaches a time threshold or the speed of the UE in the current area islower than a threshold; or if the access entity in the area where the UEcurrently locates is unlikely to be associated with another accessentity which was originally associated with the area where the UEcurrently locates. That is, the new MME determines if the distancebetween TA5 and RA2 (the RA2 is acquired from the messages sent by theUE or from the context retrieval procedure) exceeds a certain thresholdor if TA5 and RA2 is not adjacent or the association between MME andSGSN is limited (e.g., the SGSN is not in the “associable SGSN list” ofthe new MME). The RA2 may be acquired from the message sent from UE oracquired from the context retrieval procedure.

If the distance between TA5 and RA2 exceeds a certain threshold or TA5is not adjacent to RA2 or the association between the new MME and SGSNis limited or the time that the UE stays at an RAT exceeds a certainthreshold, the new MME marks the association between the new MME and theoriginally associated SGSN as invalid. Downstream data may always be thefirst to arrive at MME. When the UE triggers the predetermined conditionat the SGSN access entity, the SGSN needs to inform the MME of thisinformation. The UE is still attached to the MME. However, paging willnot be performed in the evolved network after the downstream dataarrives at the MME, instead, the downstream data will be sent to theSGSN directly and the paging will be performed in the paging areaadministered by the SGSN.

At step 906, the new MME sends a normal TAU Accept message. Since it isimpossible for the UE to move from TA5 to RA2, the UE does not need anymodification.

If any downstream data or any paging arrives, since the new MME or UPEhas marked the association with SGSN as invalid, the data or paging willnot be sent to SGSN, as illustrated in step 907 and step 907′.

At step 908, when the UE needs to be paged, the paging of UE will onlybe performed in the SAE, rather than in the RA2 corresponding to theUMTS. As such, the situation that the UE is paged in an area where it isimpossible for the UE to appear can be avoided, so that the efficiencyfor paging UE is improved.

When the UE enters a new RA, the UE initiates an RAU, as illustrated instep 909 and step 909′.

At step 910, a normal RAU procedure is performed, such as contextretrieval, registration, association. That is, when the UE enters a newRA, the UE initiates an RAU update. If the SGSN is replaced, the UEacquires context from MME or/and old SGSN. The MME sets up a newassociation with the new SGSN. The method of marking MME as invalid orcancelling association by the new SGSN is similar to marking SGSN asinvalid or cancelling association by the new MME according to theembodiments of the present invention, which is omitted herein forbrevity. If SGSN has not been replaced, the association between MME andSGSN is recovered. Then, the SGSN may also determine that theassociation with MME needs to be cancelled, which is similar to themethod according to the present embodiment.

A fourth embodiment of the present invention relates to a mobilecommunication method, as illustrated in FIG. 10. The embodiment isillustrated by way of example where the access entity in the area wherethe UE currently locates is SGSN and another RAT entity is MME. Ofcourse, the method also applies to the situation where the access entityin the area where the UE currently locates is MME and another RAT entityis SGSN.

When the predetermined condition for deactivating ISR is satisfied, thatis, when the distance between the area where the UE currently locatesand the paging area administered by the originally associated MMEexceeds a predetermined threshold; or when these two areas are notadjacent to each other; or when the access entity in the area where theUE currently locates cannot be associated with another access entitywhich was originally associated with the area where the UE currentlylocates; or the time that UE stays in the current area reaches a timethreshold or the speed of the UE in the current area is lower than athreshold, the UE accessing the new SGSN may be triggered by UE accessevent (e.g., location update, or other access) or by time or event ofthe network (e.g., timer expires), as illustrated in step 1001. Thepresent embodiment is illustrated by way of example where the UEaccesses network trigger.

At step 1002, if the content of the access entity is not the mostupdated, the new access entity may go through a context retrievalprocedure.

Step 1003 is an optional procedure such as safety authentication. If theaccess entity is a new access entity, the new SGSN may further initiatea registration procedure with HSS, as illustrated in step 1004.

At step 1005, the SGSN informs a related user plane entity. The relateduser plane entity may be an S-GW or P-GW, or other network device. Afterthe related user plane entity receives the notification, it prohibitssending data to another RAT. As such, paging within another RAT isavoided. Specifically, the method of disabling sending data to anotherRAT includes marking the related user plane entity, or releasing to achannel of another RAT entity (MME in this example), or onlyestablishing in the channel of the access entity (SGSN in this example).

At step 1006, the SGSN records de-activation information and prevents tosend data or paging request to another RAT entity after receiving data.The step is optional. At step 1006, IASA disables sending data to UPE.

A fifth embodiment of the present invention relates to a mobilecommunication method. The present invention is described in a case ofdual registration and an ISR de-activation procedure is illustrated byway of example where the UE accesses the SGSN and the SGSN performs anISR de-activation through an HSS.

FIG. 11 is a flowchart of a mobile communication method according to thefifth embodiment of the present invention;

At step 1101, the UE initiates an RAU request;

At step 1102, the SGSN acquires UE context information.

If the SGSN which the UE currently accesses is a new SGSN, the new SGSNmay need to acquire UE context information. The most updated UE contextinformation can be acquired from the old SGSN or MME or HSS. If the SGSNwhich UE currently accesses does not change and the UE contextinformation stored in the SGSN is the most updated, step 1102 may beskipped and step 1103 is performed directly.

At step 1103, the SGSN which the UE currently accesses determines toinitiate an ISR de-activation procedure.

At step 1104, the SGSN which the UE currently accesses sends a locationupdate message (Update Location) to the HSS.

The Update Location message may carry de-activation information, such asvalues for special reasons, or special value for Update Type, or otherindication parameters. Alternatively, when the UE remains the ISRactivated, the access entity of UE sends to the HSS an Update Locationrequest carrying ISR activation information (by carrying values forspecial reasons, or carrying special value for Update Type, or otherindication parameters). When the UE deactivates the ISR, the accessentity of UE does not carry activation information and the de-activationinformation is acquired from the HSS. If the S-GW changes, the messagemay also carry information of the change of the S-GW. For example, themessage may carry values for special reasons or other indications. Themessage may carry entire or partial information of the change of S-GWand/or de-activation ISR information. If the S-GW changes, thede-activation ISR may also just carry information of the change of S-GW,rather than further carrying de-activation restriction information. Assuch, the S-GW may delete all the bearers. The subsequent procedure isidentical, which may not be detailed herein.

If the SGSN which the UE currently accesses has changed, step 1105 isperformed. If the SGSN which the UE currently accesses does not change,step 1106 is performed directly.

At step 1105, the HSS sends a location deletion message to the old SGSN.

The location deletion message may carry ISR de-activation information.If S-GW changes, the message can also carry information of the change ofS-GW. For example, the message may carry values for special reasons orother indications. After the old SGSN receives the location deletionmessage, step 11051 is performed.

At step 11051, the old SGSN sends an Update PDP Context Request to theS-GW.

When the Update PDP Context Request carries values for de-activationrelated reasons or other indication indicative of only deleting bearerinformation of one access system, the old SGSN requests, in a deletebearer request, the S-GW to only delete related bearers in the SAEnetwork according to the information and also transfers Idle Mode UserPlane Termination. If the message carries related reasons or indicationsfor the change of the S-GW, the old SGSN may request, in the deletebearer request, the S-GW to delete all the bearer information of the UEaccording to the information.

The Idle Mode User Plane Termination refers to the node where thedownstream data terminates when the UE is in Idle mode, and triggers thepaging of UE. After the UE ISR is activated, since UE registers with SAEand 2G/3G simultaneously, the IMUPT is on S-GW, i.e., after downstreamdata reaches S-GW, when the S-GW discovers that the UE is in an idlestate, the UE is paged within 2G/3G and SAE. After the ISR is activated,when the UE only registers with 2G/3G, if the IMUPT is still in S-GW,S-GW needs to be informed of any change of UE in 2G/3G. This not onlyincreases the processing procedures for network and UE, but also makesno sense. Therefore, the embodiment of the present invention proposesthat, when the UE deactivates ISR and the UE only registers with 2G/3G,the IMUPT is transferred to SGSN or wireless network controller.

At step 1106, the HSS sends a location deletion message to MME.

The location deletion message requests MME to delete UE contextinformation, and may further carry the ISR de-activation information.The MME knows about the de-activation information, and step 11061 isperformed according to the ISR de-activation information. If S-GWchanges, the message can also carry information of the change of

S-GW. For example, the message may carry values for special reasons orother indications.

At step 11061, MME sends a Delete Bearer Request to S-GW.

When the Delete Bearer Request may carry values for related reasons ofde-activation indicative of only deleting bearer information of oneaccess system, the MME requests, in the Delete Bearer Request, the S-GWto only delete related bearers in the SAE network according to the ISRde-activation information and also transfers IMUPT. If the messagecarries related reasons or indications for the change of the S-GW, theold SGSN may request, in the Delete Bearer Request, the S-GW to deleteall the bearer information of the UE according to the information.

It should be noted that, in practice, step 11051 can be performed andstep 11061 can be skipped. In this case, the Delete Bear Request sent atstep 1106 does not carry ISR de-activation information. Alternatively,step 11061 can be performed and step 11051 can be skipped. In this case,the Delete Bear Request sent at step 1105 may not carry ISRde-activation information. Alternatively, other method can be employedto delete a bearer or all the bearers in the de-activation system ofS-GW. In this case, both steps 11051 and 11061 can be skipped. Step 1105and step 1106 can be performed without a specific sequence.

At step 1107, the HSS returns a location update confirmation to SGSNwhich the UE currently accesses.

At step 1108, the UE returns an RAU completion message to SGSN which theUE currently accesses.

So far, the procedure of UE accessing SGSN and de-activating ISR in adual registration case is performed. In the dual registration case, theprocedure of UE accessing

MME and de-activating ISR is similar to the above procedure. The MME mayalso directly send an Update Bearer Request to S-GW, requesting the S-GWto delete bearer information of 2G/3G system. When the S-GW changes, theMME sends a bearer create request (or Create Bearer Request) to the newS-GW. When the UE accesses MME, the transfer of IMUPT is not involved.In the above procedure, if the S-GW that the UE accesses has changed,the embodiment further involves deletion of all the related bearers ofthe UE on the old S-GW.

Further, it should be noted that even if the UE does not activate theISR, the method also applies. For example, when the UE performs a Detachoperation with ISR, the HSS records two RAT entities with which the UEregisters. Assume that the two RAT entities are not purged from the HSS(e.g., the entire UE context is deleted and the information of theentities with which the UE registers is deleted from the HSS). When theUE attaches to an RAT (e.g., SAE) again and if the entity is notchanged, the HSS may only delete the old entity of the RAT (i.e., oldMME). When the UE again enters another RAT (e.g., 2G/3G) and the ISR hasnot been activated (e.g., the SGSN accessed does not support the ISR orfor other reasons), the UE initiates an Update Location with the HSSwhich may carry values for special reasons. Such information isdelivered to the HSS (or when the ISR activated, information of acertain parameter may be carried and when the ISR is not activated, theinformation will not be carried. The de-activation information isacquired from the HSS). If the SGSN which the UE accesses changes, theHSS may initiate a Cancel Location to two entities. One is the entity tobe attached by the UE and the other is the old entity detached by the UEpreviously.

A sixth embodiment of the present invention relates to a mobilecommunication method. According to the present invention, in a case ofsingle registration, the SGSN registers with HSS and the MME registerswith SGSN, and an ISR de-activation procedure is illustrated by way ofexample where the UE accesses SGSN.

FIG. 12 is a flowchart of a mobile communication method according to thesixth embodiment of the present invention.

At step 1201, UE initiates an RAU request.

At step 1202, SGSN acquires UE context information.

If the SGSN which UE currently accesses is a new SGSN, the new SGSN mayneed to acquire UE context information. The most updated UE contextinformation can be acquired from the old SGSN or MME or HSS. If the SGSNwhich UE currently accesses dose not change and the UE contextinformation stored in the SGSN is the most updated, step 1202 is skippedand step 1203 is performed directly.

At step 1203, SGSN which the UE currently accesses determines toinitiate an ISR de-activation.

If the SGSN which the UE currently accesses has changed, since the newSGSN has not registers with HSS, step 1204 is performed. If the SGSNwhich the UE currently accesses does not change, step 1208 is performeddirectly.

At step 1204, the SGSN which the UE currently accesses sends an UpdateLocation message to HSS.

The Update Location message may carry de-activation information, such asvalues for special reasons, or special value for Update Type.Alternatively, when the UE remain ISR activated, the access entity of UEsends to the HSS an Update Location request carrying informationindicative of activating the ISR (by carrying values for specialreasons, or carrying special value for Update Type). When the UEdeactivates the ISR, the access entity of UE does not carry activationinformation and the de-activation information is acquired from the HSS.If the S-GW changes, the message can also carry information of thechange of S-GW. For example, the message may carry values for specialreasons or other indications.

At step 1205, the HSS sends a location deletion message to the old SGSN.

The location deletion message may carry the ISR de-activationinformation. The message may also carry the information of the change ofS-GW. After the old SGSN receives the location deletion message, step12051 is performed.

At step 12051, the old SGSN sends a Delete Bearer Request to S-GW.

If the ISR de-activation information carries values for related reasonsindicative of only deleting bearer information of one access system, theold SGSN requests, in a Delete Bearer Request, the S-GW to only deleterelated bearer in the SAE network according to the ISR de-activationinformation and also transfers IMUPT. If the message carries relatedreasons or indications for the change of the S-GW, the old SGSN mayrequest, in the Delete Bearer Request, the S-GW to delete all the bearerinformation of the UE according to the information.

At step 1206, the old SGSN sends a location deletion message to the MME.

The location deletion message may carry ISR de-activation information.The message may also carry the information of the change of S-GW. Sincethe MME is registered with the old SGSN, the old SGSN may send thelocation deletion message to the MME. The location deletion messagerequests MME to delete UE context information, and may further carry theISR de-activation information and/or the information of the change ofS-GW. The MME may perform step 12061 according to the ISR de-activationinformation.

At step 12061, the MME sends a Delete Bearer Request to S-GW.

If the ISR de-activation information carries values for related reasonsindicative of only deleting bearer information of one access system, theMME requests, in a Delete Bearer Request message, the S-GW to onlydelete related bearer in the SAE network according to the ISRde-activation information and also transfers IMUPT. If the messagecarries related reasons or indications for the change of the S-GW, theMME may request, in the Delete Bearer Request, the S-GW to delete allthe bearer information of the UE according to the information.

It should be noted that, in practice, step 12051 can be performed andstep 12061 can be skipped. In this case, the Delete Bear Request sent atstep 1206 does not carry ISR de-activation information. Alternatively,step 12061 can be performed and step 12051 can be skipped.Alternatively, other method can be employed to delete a bearer or allthe bearers in the de-activation system of S-GW. In this case, bothsteps 12051 and 12061 can be skipped. Step 1205 and step 1206 can beperformed without a specific sequence. If the bearer is deletedaccording to other method or according to step 12051 or 12061, then thede-activation information and/or the information of the change of S-GWis not needed in step 1204, or 1205, or 12051, or 1206, or 12061.

At step 1207, the HSS returns a location update confirmation to the SGSNwhich the UE currently accesses.

After the SGSN which the UE currently accesses receives the locationupdate confirmation, step 1209 is performed.

At step 1208, the SGSN sends a location deletion message to MME.

Since the MME registers with SGSN, the SGSN may directly send thelocation deletion message to the MME. The message may carry ISRde-activation information. The MME deletes UE context informationaccording to the ISR de-activation information and may further performstep 12081. If the S-GW changes, the message can also carry informationof the change of S-GW. For example, the message may carry values forspecial reasons or other indications. If the bearer is deleted accordingto other method, it is not necessary for the message to carry thede-activation information and/or the information of the change of S-GW,and step 12081 may not be performed.

At step 12081, the MME sends a Delete Bearer Request to S-GW.

If the ISR de-activation information carries values for related reasonsindicative of only deleting bearer information of one access system, theMME requests, in a Delete Bearer Request, the S-GW to only deleterelated bearer in the SAE network according to the ISR de-activationinformation and also transfers IMUPT. If the message carries relatedreasons or indications for the change of the S-GW, the old SGSN mayrequest, in the Delete Bearer Request, the S-GW to delete all the bearerinformation of the UE according to the information.

After the MME deletes UE context information, the MME returns aconfirmation message to SGSN. After the SGSN receives the confirmationmessage returned from MME, step 1209 is performed.

At step 1209, the UE returns an RAU completion message to SGSN which theUE currently accesses.

So far, a procedure of UE accessing the SGSN and de-activating ISR isperformed in a single registration case where the SGSN registers withHSS and MME registers with SGSN. In the single registration case, theprocedure of UE accessing MME and de-activating ISR is similar to theabove procedure. The MME may also directly send an Update Bearer Requestto the S-GW, requesting the S-GW to delete bearer information of 2G/3Gsystem. When the S-GW changes, the MME sends a Create Bearer Request tothe new S-GW. Also, the MME needs to registers with HSS and deletesregistration information of SGSN in the HSS. At the same time, when theUE accesses MME, 2G/3G system is deactivated and the transfer of IMUPTis not involved. In the above procedure, if the S-GW that the UEaccesses has changed, the embodiment further involves deletion of allthe related bearers of the UE on the old S-GW.

As shown in FIG. 13, a seventh embodiment of the present inventionrelates to a mobile communication method. According to presentinvention, in a single registration case, the MME registers with HSS andthe SGSN registers with MME, and an ISR de-activation procedure isillustrated by way of example where the UE accesses SGSN.

At step 1301, the UE initiates an RAU request.

At step 1302, the SGSN acquires UE context information.

If the SGSN which UE currently accesses is a new SGSN, the new SGSN mayneed to acquire UE context information. The most updated UE contextinformation can be acquired from the old SGSN or MME or HSS. If the SGSNwhich UE currently accesses does not change and the UE contextinformation stored in the SGSN is the most updated, step 1302 may beskipped and step 1303 is performed directly.

At step 1303, SGSN which the UE currently accesses determines toinitiate an ISR de-activation.

At step 1304, the SGSN sends an Update Location message to HSS.

The Update Location message may carry de-activation information, such asvalues for special reasons, or special value for Update Type.Alternatively, when the UE remains the ISR activated, the access entityof UE sends to the HSS an Update Location request carrying ISRde-activation information (by carrying values for special reasons, orcarrying special value for Update Type). When the UE deactivates theISR, the access entity of UE does not carry activation information andthe de-activation information is acquired from the HSS. If the S-GWchanges, the message can also carry information of the change of S-GW.For example, the message may carry values for special reasons or otherindications.

If the SGSN which the UE currently accesses has changed, after HSSreceives the location update message, step 1306 is performed after step1305 is performed. If the SGSN which the UE currently accesses does notchange, step 1306 can be skipped.

At step 1305, the HSS sends a location deletion message to MME.

The location deletion message requests the MME to delete ME contextinformation and the message may carry ISR de-activation informationand/or the information of the change of S-GW. After the MME receives thelocation deletion message, the MME performs step 13051 according to therestriction signal de-activation information.

At step 13051, the MME sends a Delete Bearer Request to S-GW.

If the ISR de-activation information carries values for related reasonsindicative of only deleting bearer information of one access system, theMME requests, in a Delete Bearer Request, the S-GW to only deleterelated bearer in the SAE network according to the ISR de-activationinformation and also transfers IMUPT. If the message carries informationof the change of the S-GW, the MME may request, in the Delete BearerRequest, the S-GW to delete all bearer information of the UE accordingto the information.

At step 1306, the MME sends a location deletion message to the old SGSN.

After the MME receives the location deletion message sent by the HSS,the MME sends the location deletion message to the old SGSN according tothe ISR de-activation information. After the old SGSN receives thelocation deletion message, step 13061 is performed. The message maycarry ISR de-activation information and/or the information of the changeof S-GW.

At step 13061, the old SGSN sends a Delete Bearer Request to S-GW.

If the ISR de-activation information carries values for related reasonsindicative of only deleting bearer information of one access system, theold SGSN requests, in a Delete Bearer Request, the S-GW to only deleterelated bearer in the SAE network according to the ISR de-activationinformation and also transfers IMUPT. If the message carries informationof the change of the S-GW, the old SGSN may request, in the DeleteBearer Request, the S-GW to delete all bearer information of the UEaccording to the information.

It should be noted that, in practice, step 13051 can be performed andstep 13061 can be skipped. In this case, the Delete Bear Request sent atstep 1306 does not carry ISR de-activation information. Alternatively,step 13061 can be performed and step 13051 can be skipped.Alternatively, other method can be employed to delete a bearer. In thiscase, both steps 13051 and 13061 can be skipped and the location bearerrequest may not carry ISR de-activation information and/or informationof the change of S-GW at step 1305 and/or 1306.

At step 1307, the HSS returns a location update confirmation to the SGSNwhich the UE currently accesses.

At step 1308, the UE returns an RAU completion message to SGSN which theUE currently accesses.

So far, a procedure of UE accessing the SGSN and de-activating ISR isperformed in a single registration case where the MME registers with HSSand SGSN registers with HSS. In the single registration case, theprocedure of UE accessing MME and de-activating ISR is similar to theabove procedure. The new MME may also directly send an Update BearerRequest to S-GW, requesting the S-GW to delete bearer information of2G/3G system. When the S-GW changes, the MME sends a Create BearerRequest to the new S-GW. Also, the MME needs to delete the registrationinformation of SGSN. At the same time, when the UE accesses MME, thetransfer of IMUPT is not involved. In the above procedure, if the S-GWthat the UE accesses has changed, the embodiment further involvesdeletion of all the related bearers of the UE on the old S-GW.

It should be noted that when the SGSN which the UE currently accesses isSGSN (e.g., SGSN of R6) of Pre-R8 (e.g., SGSN of R7), the SGSN does notsupport ISR. The SGSN which the UE currently accesses needs to establisha bearer connection with P-GW, and deletes all the related bearerinformation of UE on the S-GW. When the access entity (MME/SGSN) whichthe UE currently accesses does not support ISR, the MME/SGSN needs toestablish a bearer connection with P-GW and deletes all the relatedbearer information of UE on the S-GW. In general, when the access entitywhich the UE currently accesses does not support ISR, the methoddescribed in the above embodiment also applies.

In step 1103, step 1203, and step 1303 of the foregoing embodiments, theSGSN which the UE currently accesses determines to initiate thede-activation of the ISR. The cause for triggering to initiate the ISRde-activation may be that the distance between the area where the UEcurrently locates and the paging area administered by the originallyassociated access entity in another network exceeds the threshold, orthese two areas are not adjacent with each other; or the access entityin the area where the UE currently locates can not be associated withthe originally associated access entity in the other network (e.g., theentity which the UE accesses does not support ISR or does not allow touse ISR) or association is not required according to the configurations;or the time that the UE stays in the current access system exceeds athreshold; or the speed of the UE in the current area is lower than athreshold, etc.

In the embodiments of the above mobile communication method, althoughthe network environment and the mobility states of the UE are different,e.g., for the new SGSN which the UE accesses or the new accessed MME,the ISR de-activation procedure may be different, the ISR de-activationunder various network environment or UE mobility states follows thebelow principle. When the UE accesses an access entity of a network, theaccess entity in another network may delete, invalidate or update thecontext associated with the UE and may delete the bearer of the accessentity of other network and the S-GW or delete the registrationinformation of the access entity in the HSS. If the network which the UEaccesses is 2G/3G network, the process may further involve a transfer ofIMUPT. Also, as the S-GW which the UE accesses changes, the bearers ofthe access entity in the network and the old S-GW need to be deleted andall the bearer information related to the UE on the SGSN needs to bedeleted and the bearers to the new S-GW needs to be established. Forinstance, the UE accesses SGSN and the SGSN sends a request forestablishing PDP context to the new S-GW. The request carries relatedde-activation information and the bearer information established by theS-GW to the SGSN.

An eighth embodiment of the present invention relates to a mobilecommunication method, which applies to the single registration case andthe double registration case. When the UE accesses the originallyregistered SGSN, the SGSN decides to deactivate the ISR. Referring toFIG. 14, following steps are included.

At step 1401, when the SGSN which the UE currently accesses initiates anUpdate Bearer Request (also referred to as Update PDP Context Request)to the S-GW, where the request may carry ISR de-activation information.

At step 1402, after S-GW receives the de-activation information, theS-GW decides to delete bearer information of SAE and may transfer IMUPT.

After the deletion is completed, the S-GW returns a successful deletionresponse to the SGSN.

Other portion of the present embodiment is similar to the descriptionmentioned in the above embodiments in which the MME deletes UE contextand completes de-activation of the ISR.

Likewise, the procedure after the UE accesses MME is also similar. TheMME initiates an Update Bearer procedure with the S-GW after the MMEdecides to perform de-activation. The S-GW may delete bearer informationof 2G/3G, but may not transfer IMUPT.

As can be seen from various embodiments, in the process of the accessentity performing a location update for the UE or performing a UE accessprocedure, the embodiments may include determining whether or not thearea which the UE currently locates satisfies a predetermined condition.If the predetermined condition is satisfied and when the UE needs to bepaged, the UE is paged in the paging area administered by the accessentity and it is prohibited to page the UE in the paging areaadministered by the originally associated access entity in the othernetwork. As such, the situation that the UE is paged in an area where itis impossible for the UE to appear can be avoided, so that theefficiency for paging UE is improved.

Specifically, the embodiments of the present invention prohibit pagingthe UE in the paging area administered by the originally associatedaccess entity in another network by deleting the association with theoriginally associated access entity in another network; or by settingthe UE to a detach state via the originally associated access entity inanother network; or altering the original association; or by setting theassociation between the access entity and the originally associatedaccess entity in another network as invalid and paging the UE only inthe paging area administered by the current access entity. Variousapproaches are provided for the embodiment of the embodiments of thepresent invention.

The access entity may modify the original association in the followingways. The UE is registered with the access entity in paging area inanother network adjacent to the area where the UE currently locates. Theaccess entity is treated as a new access entity associated with thecurrent access entity in the other network. When the UE needs to bepaged, the UE is paged in the paging area administered by the accessentity and the paging area in the other network. Consequently, thenetwork side may conduct paging within the area where the UE is likelyto be within. As such, the efficiency for paging UE is further improved.

A ninth embodiment of the present invention relates to a mobilecommunication system. The system includes access entities in at leasttwo networks which accept the registration of a same UE where eachaccess entity is associated with one another. In addition, the systemalso includes a determination module, configured to determine if thearea where the UE currently locates meets a predetermined condition inthe process of the access entity performing a location update for the UEor performing UE access; and an enabling modification module, configuredto prohibit paging the UE in the paging area administered by theoriginally associated access entity in the other network when thedetermination module determines that the predetermined condition is met.

Such a predetermined condition may be that the distance between the areawhere the UE currently locates and the paging area administered by theoriginally associated access entity exceeds a predetermined threshold;or these two areas are not adjacent to each other; or the access entityin the area where the UE currently locates can not be associated withthe originally associated access entity in another network; or the timethat UE stays in an RAT exceeds a time threshold.

The enabling modification module may be used to prohibit paging the UEin the paging area administered by the originally associated accessentity in another network by deleting the association between the accessentity in the area where the UE currently locates and the originallyassociated access entity in another network; or by informing theoriginally associated access entity in another network to set UE to adetach state; or by modifying the original association; or by settingthe association between the access entity in the area where the UEcurrently locates and the originally associated access entity in anothernetwork as invalid and paging, when there is a need to page UE, the UEonly in the paging area administered by the current access entity in thearea where the UE currently locates. The enabling module prohibitspaging the UE in the paging area administered by the originallyassociated access entity in another network so that the situation thatthe UE is paged in an area where it is impossible for the UE to appearcan be avoided, and the efficiency for paging UE is improved.

The mobile communication system may further include a registrationmodule and a paging module. The registration module is configured toregister US with the access entity associated with the paging area inthe other network adjacent to the area where the UE currently locateswhen the predetermined condition is met. The access entity is treated asa new access entity in another network associated with the access entityin the area where the UE currently locates. The enabling modificationmodule modifies the original association via the registration module.The paging module is configured to page, when there is a need to pagethe UE, the UE in the paging area administered by the access entity inthe area where the UE currently locates and the paging area administeredby the newly associated access entity, i.e., the UE is paged in theadjacent paging area in another network. Consequently, the network sidemay conduct paging within the area where the UE is likely to be within.As such, the efficiency for paging UE is further improved.

Of course, if the determination module determines that the predeterminedcondition is not met, then when the UE needs to be paged, the pagingmodule pages the UE in the paging area administered by the access entityin the area where the UE currently locates and the paging areaadministered by the originally associated access entity in anothernetwork.

A tenth embodiment of the present invention relates to an access entity,The access entity includes an association module configured to associateaccess entities in another network which may accept the registration ofa same UE; a determination module, configured to determine if the areawhere the UE currently locates meets a predetermined condition in theprocess of location update for the UE or UE access; and an enablingmodification module, configured to prohibit paging the UE in the pagingarea administered by the originally associated access entity in theother network when the determination module determines that thepredetermined condition is met.

Such a predetermined condition may be that the distance between the areawhere the UE currently locates and the paging area administered by theoriginally associated access entity exceeds a predetermined threshold;or these two areas are not adjacent to each other; or the current accessentity can not be associated with the originally associated accessentity in another network.

The enabling modification module may be used to prohibit paging the UEin the paging area administered by the originally associated accessentity in another network by deleting the association between thecurrent access entity and the originally associated access entity inanother network; or by informing the originally associated access entityin another network to set UE to a detach state; or by modifying theoriginal association; or by setting the association between the currentaccess entity and the originally associated access entity in anothernetwork as invalid and paging, when there is a need to page UE, the UEonly in the paging area administered by the current access entity. Theenabling module prohibits paging the UE in the paging area administeredby the originally associated access entity in another network so thatthe situation that the UE is paged in an area where it is impossible forthe UE to appear can be avoided, and the efficiency for paging UE isimproved.

The access entity may further include a registration module and a pagingmodule. The registration module is configured to register UE with theaccess entity associated with the paging area in the other networkadjacent to the area where the UE currently locates when thepredetermined condition is met. The access entity is treated as a newaccess entity in another network associated with the current accessentity. The enabling modification module modifies the originalassociation via the registration module. The paging module is configuredto page the UE in the paging area administered by the current accessentity when the UE needs to be paged and inform the newly associatedaccess entity to page the UE in the paging area administered by thenewly associated access entity. Consequently, the network side mayconduct paging within the area where the UE is likely to be within. Assuch, the efficiency for paging UE is further improved.

The embodiment of the present invention is not limiting as to whether ornot to integrate MME/S-GW and integrate S-GW and P-GW regardingembodiments of the present invention. Some of the above embodiments aredescribed in an example where the MME/S-GW/P-GW are integrated. However,such embodiments also apply to the procedure where the MME/S-GW/P-GW areseparated.

The foregoing embodiments are described in an example where the UE iswithin SAE and UE is triggered by the location update. Embodiments wherethe UE is triggered in other manners or by the network are relativelysimple, the description of which are omitted herein for brevity.

Referring to FIG. 15, an access entity 1500 is also provided accordingto one embodiment of the present invention. The access entity includesan association module 1501 for associating access entities in anothernetwork which accept the registration of a same UE. The access entityalso includes:

an enabling modification module 1502, configured to prohibit paging UEin a paging area administered by an originally associated access entityin another network when an access entity in one of at least two networksperforms a location update for the UE or other access procedure.

The access entity further includes:

a transfer notification module, configured to inform the originallyassociated access entity in another network to transfer IMUPT; and

an enabling modification module, configured to prohibit paging the UE inthe paging area administered by the originally associated access entityin another network in such manners as to inform the HSS and let the HSSinform the originally associated access entity in another network todelete the association with an access entity in one of at least twonetworks or inform the originally associated access entity in anothernetwork to delete association with an access entity in one of at leasttwo networks.

Referring to FIG. 16, a bearer transfer system is further providedaccording to an embodiment of the present invention. The system includesan access entity 1600 in one of at least two networks and a ServingGateway 1601; wherein the access entity 1600 in one of at least twonetworks is configured to send a bearer transfer request to the ServingGateway 1601.

After receiving the bearer transfer request, the Serving Gateway 1601deletes bearer information of other network which is originallyassociated with the access entity in one of the at least two networks.

The bearer transfer system further includes an originally associatedaccess entity in another network and an HSS.

The HSS is configured to send a location deletion message to theoriginally associated access entity in another network after receivingan Update Location message from the access entity in one of the at leasttwo networks.

The originally associated access entity in another network is configuredto send a bearer transfer request to the Serving Gateway after receivingthe location deletion message.

The bearer transfer system further includes an old access entity in oneof two networks.

The HSS is further configured to send a location deletion message to theold access entity in one of the two networks.

After receiving the location deletion message, the old access entity inone of the networks sends the bearer transfer request to the ServingGateway.

After receiving the bearer transfer request, the Serving Gateway deletesbearer information of other network which is originally associated withthe access entity in one of the at least two networks.

The bearer transfer system further includes an old Serving Gateway;

The access entity in one of the two networks is further configured tosend a Create Bearer request to the Serving Gateway and send a locationdeletion message to the originally associated access entity in anothernetwork.

The serving network is further configured to return a Create Bearerresponse to the access entity in one of the two networks after receivingthe Create Bearer request.

The originally associated access entity in another network or the oldaccess entity in one of the two networks is configured to send a bearertransfer request to the old Serving Gateway after receiving the locationdeletion message.

The old Serving Gateway is configured to delete bearer information ofthe UE after receiving the bearer transfer request.

Although several preferred embodiments have been presented inconjunction with the drawings, it is appreciated by those skilled in theart that any modification in formalities and details can be made withoutdeparting from the spirit and scope of the present invention.

1. A system implemented in a scenario where a user equipment is movingwithin a coverage of a first network and a second network, wherein theuser equipment is registered with both a first access entity of thefirst network and a second access entity of the second network, and afirst association is established between the first access entity and thesecond access entity so that when the user equipment needs to be paged,the user equipment is paged in a paging area administered by the firstaccess entity and a paging area administered by the second access entityaccording to the first association, and the system comprises: the userequipment, configured to send a location update request to a thirdaccess entity of the second network; and the third access entity,configured to receive the location update request from the userequipment, acquire information of the first access entity from thelocation update request and determine whether a predetermined conditionis satisfied, wherein the predetermined condition comprises one or moreof the following: a distance between an area where the user equipment iscurrently located and the paging area administered by the first accessentity exceeds a predetermined threshold; the third access entity cannotbe associated with the first access entity; and the speed of the userequipment in a current access entity system is lower than a threshold,and wherein if the predetermined condition is not satisfied, the userequipment is paged through the first access entity, and if thepredetermined condition is satisfied, the user equipment is not pagedthrough the first access entity.
 2. The system of claim 1, wherein thethird access entity is further configured to inform the first accessentity to set the locally stored state of the user equipment to adetached state or a deactivated state if the predetermined condition issatisfied, so that the user equipment is not paged by the first accessentity.
 3. The system of claim 1, wherein the third access entity isfurther configured to inform, a related user plane equipment, andinstruct the user plane equipment to prohibit data or paging requestfrom being sent to the first access entity if the predeterminedcondition is satisfied.
 4. The system of claim 1, wherein the thirdaccess entity is further configured to inform, a related user planeequipment, and instruct the user plane equipment to release a channelwith the first access entity or to only establish a channel with thethird access entity, if the predetermined condition is satisfied.
 5. Thesystem of claim 1, wherein the third access entity is further configuredto establish a second association between the first access entity andthe third access entity, if the predetermined condition is notsatisfied; and wherein when the user equipment needs to be paged, theuser equipment is paged in the paging area administered by the firstaccess entity and a paging area administered by the third access entityaccording to the second association.
 6. The system of claim 1, whereinthe third access entity is further configured to send an update bearerrequest which indicates an Idle mode Signaling Reduction (ISR)de-activation to a related user plane equipment, if the predeterminedcondition is satisfied, so as to make the related user plane equipmentdeleting a bearer of the first access entity.
 7. The system of claim 1,wherein the third access entity is further configured to inform, arelated user plane equipment to transfer an Idle Mode User PlaneTermination to the third access entity if the predetermined condition issatisfied.
 8. The system of claim 1, wherein the third access entity isfurther configured to select a fourth access entity of the firstnetwork, establish a third association with the fourth access entity ifthe predetermined condition is satisfied; and wherein when the userequipment needs to be paged, the user equipment is paged in a pagingarea administered by the third access entity and a paging areaadministered by the fourth access entity according to the thirdassociation.
 9. The system of claim 1, wherein the first network is asecond generation or third generation (2G/3G) network, and the secondnetwork is an evolved network; or the first network is an evolvednetwork, and the second network is a 2G/3G network.
 10. A userequipment, wherein the user equipment is moving within a coverage of afirst network and a second network, and is registered with both a firstaccess entity of the first network and a second access entity of thesecond network; wherein a first association is established between thefirst access entity and the second access entity so that when the userequipment needs to be paged, the user equipment is paged in a pagingarea administered by the first access entity and a paging areaadministered by the second access entity according to the firstassociation, and wherein the user equipment comprises: a transmitter,configured to send a location update request to a third access entity ofthe second network; wherein the location update request triggers thethird access entity to acquire information of the first access entityfrom the location update request and determine whether a predeterminedcondition is satisfied, wherein the predetermined condition comprisesone or more of the following: a distance between an area where the userequipment currently locates and the paging area administered by thefirst access entity exceeds a predetermined threshold; the third accessentity cannot be associated with the first access entity; and the speedof the user equipment in a current access entity system is lower than athreshold, and wherein if the predetermined condition is not satisfied,the user equipment is paged through the first access entity, and if thepredetermined condition is satisfied, the user equipment is not pagedthrough the first access entity.
 11. The user equipment of claim 10,wherein the first network is a second generation or third generation(2G/3G) network and the second network is an evolved network; or thefirst network is an evolved network, and the second network is a 2G/3Gnetwork.
 12. A method for use in a scenario where a user equipment ismoving within a coverage of a first network and a second network,wherein the user equipment is registered with both a first access entityof the first network and a second access entity of the second network,and a first association is established between the first access entityand the second access entity so that when the user equipment needs to bepaged, the user equipment is paged in a paging area administered by thefirst access entity and a paging area administered by the second accessentity according to the first association, and the method comprises:sending, by the user equipment, a location update request to a thirdaccess entity of the second network; wherein the location update requesttriggers the third access entity to acquire information of the firstaccess entity from the location update request and determine whether apredetermined condition is satisfied, wherein the predeterminedcondition comprises one or more of the following: a distance between anarea where the user equipment currently locates and the paging areaadministered by the first access entity exceeds a predeterminedthreshold; the third access entity cannot be associated with the firstaccess entity; and the speed of the user equipment in a current accessentity system is lower than a threshold, and wherein if thepredetermined condition is not satisfied the user equipment is pagedthrough the first access entity, and if the predetermined condition issatisfied, the user equipment is not paged through the first accessentity.
 13. The method of claim 12, wherein the first network is asecond generation or third generation (2G/3G) network and the secondnetwork is an evolved network; or the first network is an evolvednetwork, and the second network is a 2G/3G network.